2694a64ebb
We currently compute the target scale from the allocated height, which means that it only becomes available after thumbnails have been allocated at least once at their expanded height. As the minimap is initially hidden, this only happens after it is expanded for the first time, which means the corresponding transition is not animated. In order to allow for a fix, compute the target height ourselves to allow the scale computation to work independently from the expand factor. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3331>